1. Field of the Invention
The present invention relates to a urinal with a sanitation device in which the whole of a trap unit having a water seal formed by urine or component parts constituting the trap unit are interchangeable, and in which a sanitary condition is maintained by using a chemical agent.
2. Description of the Related Art
Flush urinals in which a sanitary condition is maintained by supplying water each time after use have come into wide use. Human urine contains various bacteria. If urine remains in the bowl of a urinal and other portions after use, various bacteria in the urine multiply increasingly with passage of time and produce ammonia by decomposing urea in the urine, thereby generating an ammonia smell and urine scale (solid matters such as calcium phosphate and magnesium phosphate derived from constituents of urine). In an ordinary flush urinal, therefore, water is delivered into the bowl of the urinal to flush away urine remaining in the bowl.
In this conventional flush urinal, water is delivered into the bowl and caused to flow into a trap connected to the bowl downstream of the same and replace urine retained in the trap, thereby discharging the urine. Further, urine remaining in a drain tube connected downstream of the trap is flushed away with water supplied from the bowl through the trap. Thereafter, delivery of water is stopped, with the trap filled with water. In this way, urine remaining in the bowl and other portions is flushed away before various bacteria in the urine multiply largely, thereby inhibiting the production of ammonia and urine scale and preventing the generation of a smell and clogging of the drain tube with urine scale. Water filling the trap functions as a water seal to prevent a backflow of a smell from the drain tube. After flushing, only water exists in the trap. Therefore, even when the water seal in the trap evaporates and diffuses in the toilet room where the urinal is installed, the evaporated constituents do not act as a cause of a smell.
Under circumstances as a result of the increase of environmental consciousness in recent years, a high level of water conservation performance is required of facilities and appliances using water. This is also the case with urinals. In flush urinals such as described above, however, flushing urine in the bowl, replacement and discharge of urine in the trap and flushing of urine in the drain tube are performed by delivering water one time into the bowl. A comparatively large amount of water is needed to perform those operations with reliability. From the viewpoint of water conservation, therefore, there is a demand for further reducing the amount of water to be used.
A non-flush urinal is known which has a trap such as described in National Publication of International Patent Application No. 2007-518005, and which is an example of a urinal designed to meet a water conservation requirement. In an ordinary flush urinal, water is supplied each time after use and water retained in a trap is used as a water seal. In the non-flush urinal having the trap described in National Publication of International Patent Application No. 2007-518005, supply of water after use is not performed in principle; urine retained in the trap is used as a water seal.
In the case where urine retained in the trap is used as a water seal, there is an apprehension that ammonia in the urine evaporates and diffuses in the toilet room to generate a smell, and that urine scale is generated in the trap. To solve this apprehended problem, a chemical agent is used in the trap described in National Publication of International Patent Application No. 2007-518005. A chemical agent such as citric acid is disposed at such a position as to contact urine flowing into the trap, and a part of the chemical agent dissolved by contact with the urine flows into the trap together with the urine. The trap described in National Publication of International Patent Application No. 2007-518005 is designed to supply a chemical agent into the trap by utilizing urine from a user in order to inhibit multiplication of various bacteria in urine retained in the trap and prevent generation of a smell and urine scale.
This trap is of such a construction (cartridge) as to be provided at a low cost and interchangeable. Therefore, the trap may be replaced with a new one to enable continued use of the urinal, for example, in a situation where the above-described chemical agent disappears during use of the urinal; the generation of urine scale in the trap progresses; and the performance in discharging urine from the trap becomes lower.
In a case where a chemical agent is supplied into a trap by utilizing urine from a user, as in the trap-interchange-type urinal described in National Publication of International Patent Application No. 2007-518005, however, stoppage of supply of the chemical agent into the trap occurs, for example, during a time period at a weekend during which the frequency of use is low, as in a case where the urinal is installed in a toilet room in an office building. In such a case, multiplication of various bacteria in the retained urine is not inhibited; the production of ammonia progresses over the weekend; and a smell is generated at the beginning of the next week.
In the trap-interchange-type urinal described in National Publication of International Patent Application No. 2007-518005, urine remains in the bowl since water is not supplied. The urinal described therein is incapable of coping with the generation of a smell and urine scale generated from the remaining urine.